The invention relates to an apparatus for the production of coatings with a uniform thickness profile on substrates by cathode sputtering, consisting of a coating chamber, a sputtering cathode held fixedly therein, and a substrate carriage which is held and guided on rails and/or between sliding or rolling bodies and can be moved through the coating chamber transversely of the sputtering cathode.
An apparatus is known (DE-OS 3306 870), which consists of a sputtering cathode and substrate holders on a common chassis which can travel while producing a continuous rotatory movement of the substrate holders with respect to the sputtering cathode. For this purpose a driver wheel is disposed on the chassis, whose axis of rotation is perpendicular to the direction of travel; a drive means is disposed parallel to the direction of travel by which the driver wheel is engaged on a portion of its path, and the driver wheel is coupled with a substrate holder. The drive means is in the form of an endless chain which is guided over two sprockets disposed in tandem in the direction of travel, which can be rotated by a drive motor, and each driver wheel cooperates through a bevel gear transmission with a substrate holder.
This known apparatus has the disadvantage, among others, of being extraordinarily complex and bulky, and at the same time less reliable in operation.
The present invention sets for itself the task of creating an apparatus of the type described above, which will operate without mechanical gearing, make possible an especially low configuration, and run without maintenance, so that in no case will it be necessary to open the coating chamber.
This is accomplished according to the invention by the fact that one or more substrate disks are rotatably mounted on the substrate carriage, on its side facing the cathode. The axes of rotation of these disks are disposed transversely of the plane of movement of the substrate carriage. Motor-driven shafts equipped with magnets are journaled on the side of the substrate carriage facing away from the cathode in the coating chamber, and their longitudinal axes are disposed in plane parallel to the plane of movement of the substrate carriage.
Advantageously also, the substrate carriage is in the form of a substantially rectangular plate on whose upper side a plurality of substrate disks are journaled, while the corresponding axes of rotation are each brought downward through bearing bores in the substrate carriage and joined for co-rotation with rotor disks which cooperate with the shafts provided with magnets.
Preferably, each substrate disk as well as each corresponding rotor disk is provided with a hub, and these hubs are joined together by a shaft; each pair of hubs cooperates with a rolling bearing whose bearing cage is held on the substrate carriage.
In order to produce a disk current that is especially effective in the sense of providing rotation of the substrate disks, the shafts running transversely of the direction of movement of the substrate carriage are of such dimensions that the magnets affixed to the shafts run approximately from the vicinity of the outer edge of a rotor disk approximately to the center of the wheel.
Advantageously, the shaft for mounting a magnet has a shaft-like opening in the area of the rotor disk, into which one or more permanent magnets are inserted, the permanent magnets being of such dimensions that they fill up the shaft-like opening and otherwise are adapted to the rotational contour of the shaft.